Method and apparatus for treating fluent materials

Abstract

A process for heating fluids to a relatively high temperature, such as sterilization temperature, in which the fluid, such as a liquid, is heated by direct contact with steam while it is in the form of a very thin, free-falling film or a continuous falling stream so that heating of the fluid is accomplished without the fluid coming into contact with any surface and particularly metal surfaces which are hotter than the fluid product being heated and with minimum agitation and turbulence of the fluid product. This procedure enables maximum and uniform heat penetration in a minimum time interval with the film or stream being maintained as thin as possible and unbroken by introducing steam at a relatively low velocity in a large volume vessel. A flow control is incorporated into the apparatus to maintain a constant flow rate of fluid and to maintain a constant and critical fluid level in the bottom portion of the large volume vessel with the flow characteristics of the apparatus and the internal forces produced by the apparatus serving to counterbalance each other to provide a relatively simple but yet accurate flow rate and liquid level controls for the fluid being heated.

What is claimed as new and desired to be secured by Letters Patent of the United States is: 
     
       1. A method for maintaining a stable fluid level in a pressurized fluid processing system including a vessel, independent of large changes in system dynamics, comprising the steps of: establishing a desired flow rate into said system,   permitting said desired flow rate to vary independently of a predetermined fluid level at the bottom of the said vessel,   pressurizing and heating said system to a desired level;   collecting said fluid with said predetermined fluid level at the bottom of said vessel,   setting constant parameters for a continuous flow outlet means for said system whereby said predetermined fluid level is maintained in said system; and   maintaining said setting regardless of said variations in said flow rate into said system.   
     
     
       2. An apparatus for treating fluent material with a heated gas having an initial flow velocity comprising: a pressure vessel,   dispensing means mounted within said vessel for forming at least one isolated, continuous film of said fluent material,   baffle means mounted within said pressure vessel for reducing said initial flow velocity of said heated gas and for distributing said gas within said vessel to achieve rapid heating of said isolated, continuous film of said fluent material while subjecting said film to minimum of physical perturbation,   fluid outlet means coupled to said vessel for withdrawing treated fluent material therefrom;   holding tube means coupled to said fluid outlet means for maintaining said fluent material at a selected temperature for a selected time interval; and   fluid collecting means within said pressure vessel for intercepting said isolated, continuous film and for supplying said treated fluent material to said outlet means with a minimum of physical agitation; wherein said dispensing means comprises:   a structure forming a chamber for receiving a quantity of said fluent material, said structure having a discharge aperture formed therein; and,   distribution means positioned within said structure for distributing substantially equal quantities of said fluent material to each segment of said discharge aperture; and wherein the cross-sectional areas of said outlet means and holding tube means are fixed so as to provide balanced force control means for maintaining a stable liquid level in said pressure vessel independent of changes in system dynamics.   
     
     
       3. The apparatus of claim 2 wherein said distribution means comprises: a structural member having a non-uniform distribution of apertures therethrough, said apertures distributed to form a varying net opening through said structural member.   
     
     
       4. A dispensing head as in claim 3 wherein: said distribution of apertures includes a series of openings of progressively smaller size.   
     
     
       5. A dispensing head as in claim 3, wherein: said distribution of apertures includes a plurality of openings of similar size spaced to provide a progressively smaller density of openings through said structural member.   
     
     
       6. A dispensing head as in claim 3, wherein said distributing means comprises: a generally flat plate dividing said chamber within said elongated structure into two sub-chambers.   
     
     
       7. A dispensing head as in claim 3, wherein said distributing means comprises: a tubular member disposed within said elongated structure and extending along the axis thereof.   
     
     
       8. An apparatus as in claim 2, wherein said dispensing means comprises: supply pipe means for carrying a flow of said fluent material,   branch pipe means coupled to said supply pipe means for dividing said flow therein into a plurality of components; and   a plurality of film forming head means coupled to said branch pipe means for forming a plurality of thin, isolated, continuous films of said fluent material.   
     
     
       9. An apparatus as in claim 2, wherein said fluid collecting means comprises: a conical lower section of said pressure vessel,   a layer of non-metallic, chemically inert material of low thermal conductivity covering said conical lower section; and,   means associated with said conical lower section for preventing excessive heating thereof.   
     
     
       10. An apparatus as in claim 2, wherein said fluid collecting means comprises: a conical element formed of a non-metallic, chemically inert material of low thermal conductivity supported within a lower portion of said pressure vessel.